 /* crypto/bn/bn_rand.c */

 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)

 * All rights reserved.

 *

 * This package is an SSL implementation written

 * by Eric Young (eay@cryptsoft.com).

 * The implementation was written so as to conform with Netscapes SSL.

 * 

 * This library is free for commercial and non-commercial use as CrLONG32 as

 * the following conditions are aheared to.  The following conditions

 * apply to all code found in this distribution, be it the RC4, RSA,

 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation

 * included with this distribution is covered by the same copyright terms

 * except that the holder is Tim Hudson (tjh@cryptsoft.com).

 * 

 * Copyright remains Eric Young's, and as such any Copyright notices in

 * the code are not to be removed.

 * If this package is used in a product, Eric Young should be given attribution

 * as the author of the parts of the library used.

 * This can be in the form of a textual message at program startup or

 * in documentation (online or textual) provided with the package.

 * 

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. All advertising materials mentioning features or use of this software

 *    must display the following acknowledgement:

 *    "This product includes cryptographic software written by

 *     Eric Young (eay@cryptsoft.com)"

 *    The word 'cryptographic' can be left out if the rouines from the library

 *    being used are not cryptographic related :-).

 * 4. If you include any Windows specific code (or a derivative thereof) from 

 *    the apps directory (application code) you must include an acknowledgement:

 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"

 * 

 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 * 

 * The licence and distribution terms for any publically available version or

 * derivative of this code cannot be changed.  i.e. this code cannot simply be

 * copied and put under another distribution licence

 * [including the GNU Public Licence.]

 */



#include "crypto/CrBNConfig.h"

#ifdef _BN_RAND_C



//#include <stdio.h>

#include "crypto/CrSMemMgr.h"

#include "crypto/CrBN.h"  

#include "crypto/CrBNLcl.h"





#ifdef SWC_RANDOM_NUMBER

#include "crypto/CrSwcRand.h"

#else

#include <time.h>

#include "crypto/CrRand.h"

#endif  



#ifndef SWC_RANDOM_NUMBER

void RAND_bytes( CrUINT8 *buf,CrINT32 num)

{

	CrINT32 i;

	for(i=0;i<num;i++)

		buf[i] = (CrUINT8)rand();

}



void RAND_seed( CrUINT8 *buf,CrINT32 num)

{

	srand((unsigned)time(NULL));

}

#endif



CrINT32

BN_rand(

	BIGNUM*	rnd,

	CrINT32 bits,

	CrINT32 top,

	CrINT32 bottom)

{

	CrUINT8 *buf=NULL;

	CrINT32 ret=0,bit,bytes,mask;

#ifndef SWC_RANDOM_NUMBER

	time_t tim;

#endif





	bytes=(bits+7)/8;

	bit=(bits-1)%8;

	mask=0xff<<bit;



	buf=(CrUINT8 *)SMalloc(bytes);

	

	if (buf == NULL)

	{

#ifndef NO_SSLEAY_ERROR

		BNerr(BN_F_BN_RAND,ERR_R_MALLOC_FAILURE);

#endif

		goto err;

	}



	 /* make a random number and set the top and bottom bits */

#ifdef SWC_RANDOM_NUMBER

	if (getRandomBytes(buf, (CrUINT32)bytes) != 0 )

		goto err;

#else

	time(&tim);

	RAND_seed((CrUINT8 *)&tim,sizeof(tim));



	RAND_bytes(buf,(CrINT32)bytes);

#endif

	

	if (top)

	{

		if (bit == 0)

		{

			buf[0]=1;

			buf[1]|=0x80;

		}

		else

		{

			buf[0]|=(3<<(bit-1));

			buf[0]&= (CrUINT8)(~(mask<<1));

		}

	}

	else

	{

		buf[0]|=(1<<bit);

		buf[0]&= (CrUINT8)(~(mask<<1));

	}



	if (bottom)  /* set bottom bits to whatever odd is */

		buf[bytes-1]|=1;

	if (!BN_bin2bn(buf,bytes,rnd))

		goto err;



	ret=1;



err:

	if (buf != NULL)

	{

		SMemset(buf,0,bytes);

		SFree(buf);

	}



	return(ret);

}









#endif //end of #ifdef _BN_RAND_C




